The present invention relates to a remote control device having a microphone for a tape recorder.
A recently developed tape recorder includes a remote control arrangement capable of actuating various operating modes such as recording and reproducing from a remote location.
FIG. 1 shows a remote control device for conventional tape recorder. Here a body 1 of a remote control device includes a microphone 2, mode operating switches such as a recording (REC) switch 3, a playing (PLAY) switch 4, and a stop (STOP) switch 5, and a display arrangement 15. The display arrangement 15 includes an input detecting circuit 6 for detecting the operating condition of the tape recorder, that is, whether the various operating modes are switched on or off, a display circuit 7 connected to the input detecting circuit 6 for displaying the operating condition of the various operating modes, and a display element such as a light emitting diode 8 connected to the display circuit 7 for displaying the operating condition of various operating modes by emitting light. Each of the switches 3, 4 and 5 has a pair of switch segments. The microphone 2 is connected to remote control connecting terminals t.sub.1 and t.sub.2 of the remote control device through lead wires l.sub.1 and l.sub.2. Switch segments at one side of respective switches 3, 4 and 5 are connected to remote control connecting terminals t.sub.3, t.sub.4 and t.sub.5 of the remote control device through lead wires l.sub.3, l.sub.4 and l.sub.5, respectively. Switch segments at other side of respective swiches 3, 4 and 5 are connected in common with each other and connected to a remote control connecting terminal t.sub.6 of a positive power source. The remote control connecting terminals t.sub.3, t.sub.4, t.sub.5 and t.sub.6 are connected to the input detecting circuit 6 through lead wires l'.sub.3, l'.sub.4, l'.sub.5 and l'.sub.6, respectively. The input detecting circuit 6 is connected to the light emitting diode 8 through the display circuit 7, and also connected to a remote control connecting terminal t.sub.7 for negative power source through a lead wire l.sub.7.
The remote control device body 1 thus formed is connected to a body 10 of the tape recorder through a remote control connection cord 9 which comprises a plurality of lead wires. The tape recorder body 10 includes remote control connecting terminals t.sub.11 to t.sub.17 coresponding to the remote control connecting terminals t.sub.1 to t.sub.7 of the remote control device body 1. The connecting terminal t.sub.11 is connected to a microphone amplifier system 11 through a lead wire l.sub.11. The connecting terminal t.sub.12 is connected to a grounded point through a lead wire l.sub.13. The connecting terminals t.sub.13 to t.sub.17 are connected to a main control circuit 12, for example, a large scale integrated circuit (LSI) through lead wires l.sub.13 to l.sub.17, respectively. The main control circuit 12 serves for controlling a motor control system and a recording and reproducing amplifier system (both are not shown) by receiving information which represents operation of various kinds of modes such as recording or reproducing, that is, orders to make the recorder operative.
In the remote control device thus constructed when the recording switch 3 is turned on the information representing the recording mode is supplied to the main control circuit 12 of the tape recorder body 10 through a signal path formed by the lead wire l.sub.3, the connecting terminal t.sub.3, the remote control connection cord 9, the connecting terminal t.sub.13 and the lead wire l.sub.13, so that the tape recorder body 10 goes into recording mode. In the same way, the playing switch 4 or the stop switch 5 is turned on the information representing or playing mode or stop mode is supplied to the main control circuit 12 of the tape recorder 10 so that the tape recorder 10 enters the playing mode or stop mode.
In this case when operating switches 3, 4 and 5 of various modes are turned on the supply voltage is applied to the input detecting circuit 6 through lead wires l'.sub.3 to l'.sub.6 thereby energizing the light emitting diode 8 through the display circuit 7. The light emitting diode 8, therefore, is utilized to confirm operation of the tape recorder caused by the switch-on action of the switches 3, 4 and 5.
The main control circuit 12 of the tape recorder body 10 has the function of temporarily memorizing information on various operating modes, as various kinds of operating switches 3, 4 and 5 a switch of so-called non-locked type is often used which functions only when pushing it. In this case the light emitting diode 8 emits light only when various mode switches are utilized only to confirm the switching-on action thereof. Therefore, it is impossible to detect on the remote control device whether or not the tape recorder body 10 operates with certainty.
In order to eliminate the above disadvantage, a recently developed remote control device is constructed as shown in FIG. 2 in which like reference characters designate corresponding parts shown in FIG. 1. In this remote control device the input detecting circuit 6 is connected to the main control circuit 12 of the tape recorder 10 through a signal path formed by a lead wire l.sub.8, a remote control connecting terminal t.sub.8, a signal line 13 enclosed in the remote control cord 9, a remote control and a lead wire l.sub.18, so that information on operation of the tape recorder body 10 is supplied to the input detecting circuit 6 through the above signal path thereby lighting the light emitting diode 8. In this manner, even if a switch of the non-locked type is used as various mode switches 3, 4 and 5, the operation of the tape recorder 10 can be detected on the remote control device with the light of the light emitting diode 8.
According to such a construction, an additional new signal line 13 is required in order to supply the actuating information to the input detecting circuit 6 from the main control circuit 12 of the tape recorder 10. This makes the remote control connection cord 9 thicker by the amount of the additional signal line and effectively produces trouble. In addition thereto the remote control connecting terminals t.sub.8 and t.sub.18 are also necessary so that the number of components increase and the remote control device becomes expensive.
In general, a tape recorder is constructed so that when it is turned on to the recording mode and the playing mode the power supply source is thrown to the motor control system and the recording and reproducing amplifier system and is shut-off with the stop mode and the tape end detected signals. The power voltage, therefore, is supplied to the amplifier system 11 of the tape recorder in the recording mode and playing mode and also supplied to the microphone 2 of the remote control device 1.